<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>1</title>
    <style>
        .dropdown{
            position: relative;
            display: inline-block;
        }
        .dropdown-content{
            display: none;
            position: absolute;
            background-color: #dddddd;
            min-width: 160px;
            box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
            padding: 12px 16px;
            z-index: 0;
        }
        .dropdown:hover .dropdown-content{
            display: block;
        }
        .a{
            width: 200px;
            height: 200px;
            background-color: rgb(148, 39, 39);
        }
    </style>
</head>
<body>
    <div class="dropdown">
　　    <span>php中文网</span>
　　    <div class="dropdown-content">
　　        <p>HelloWorld!</p>
　　        <p>HelloWorld!</p>
　　    </div>
　　</div>
    <div class="a"></div>
</body>
</html>